Water heaters



May 29, 1956 M, wlLLlAMs ETAL 2,748,252

WATER HEATERS Filed Oct. 4, 1954 l 4 Sheets-Sheet l INVENTORS /O MMIcHH/:lJ mums GERHLD H. KRESKE Rforrley May 29, 1956 M. WILLIAMS ErAL2,748,252

WATER HEATERS Filed Oct. 4, 1954 4 Sheets-Sheet 2 INVENTORS M MICHHE/JWzL/.mms

GERHLD H. KRESKE May 29 i956 M. WILLIAMS EVAL WATER HEATERS 4Sheets-Sheet 5 Filed OCT.. 4, 1954 m un MI NL nu mw I.- F. H H C I M`""'GERnL.n H. KRESKE H torney May 29, 1956 M. WILLIAMS ETAI- WATERHEATERS 4 Sheets-Sheet 4 Filed 061,. 4, 1954 INVENTORS mw y e ma Mm L RM n.. K H ww, www .HH HR K E M G WATER HEATERS Michael Williams andGerald H. Kreske, Warren, Ohio, assignors to Edwin L. Wiegand Company,Pittsburgh, Pa., a corporation of Pennsylvania Application October 4,1954, Serial No. 460,044

15 Claims. (Cl. 219-38) The present invention relates to water heaters,more particularly to water heaters of the "type having a water storagetank about which is disposed an electric resistance heating-element, andthe principal object of our invention is to provide new and improvedwater heaters of the character described.

Water heaters ofthe type yhaving one or more electric resistance heatersdisposed about the exterior of a water storage tank have been known fora considerable time. However, this particular type of water heater hasnot achieved wide commercial success over the more common type in whichan electric heater is immersed within the tank, in spite of the factthat the so called wrap-around heater eliminates the problem of elementcorrosion which has plagued the immersion type of heater.

One of the factors that limited wide-spread use of wraparound waterheater constructions has been the inability of the trade to devise anefficient yet economical construction for fastening the electric heaterto the wall of the tank wherein good therma-l conductivity between thetank and the heater will be maintained and wherein the electric heatermay be replaced, when necessary, without dismantling the water heater.

The present invention provides eicient Wrap-around water heaters whichare economical to manufacture and to maintain in operation. These andother advantages will become apparent from a study of the followingdescription and from the drawings appended hereto.

ln the drawings accompanying this specification and forming a part ofthis application there are shown, for purpose of illustration, severalembodiments which our invention may assume, and in these drawings:

` Figure l is a transverse sectional view of a waterpheater constructedin accordance with one embodiment of our invention,

Figure 2 is a fragmentary elevational view, partially in section, of theembodiment illustratedl in Figure l,

Figure 3 is a fragmentary, enlarged longitudinal sectional viewgenerally corresponding to the line 3-3 of Figure 1,

vFigure 4 is an enlarged, perspective View of a detail employed in theembodiment shown in Figures il, 2 and 3,

Figure 5 is a fragmentary elevational View of a Water heater, partiallyin section, illustrating a modified construction,

Figure 6 is an enlarged elevational View of a detail employed in theembodiment illustrated in Figure 5, this detail being shown in oneposition in full lines and in another position in dot dash lines,

Figure 7 is a further enlarged, perspective view of the detail shown inFigure 6,

Figure 8 is a transverse sectional view of a 4water heater illustratinganother embodiment of our invention,

Figure 9 is a fragmentary View similar to Figure 8 but considerablyenlarged and omitting certain vparts in the interest of clarity.

y autres Patented May 29, 1956 ACC Figure 1Q is a fragmentaryelevational view, partially insection, of the embodiment shown in Figure8,

Figure 1l is a transverse sectional View of a water heater illustratingstill another embodiment of our invention,

Figure 12 is a fragmentary enlarged sectional view generallycorresponding to the line l2-l2 of Figure ll,

Figure 13 is a fragmentary longitudinal sectional view of a water heaterillustrating a further embodiment of the invention, and

Figure 14 is a reduced size perspective view of a detail employed in theembodiment shown in Figure 13.

ln the embodiment illustrated in Figures l, 2 and 3, there is shown awater storage tank l() which is encased in the usual jacket 1l. Thespace between the jacket l1 and the tank 1li is adapted to be filledwith the usual heat insulating material 12 such as fiberglass or thelike. Although not shown, the usual means will be provided whereby theinterior of the tank 10 may be connected to the lines which supply itwith water to be heated and -also to the lines which carry hot Waterfrom the tank to the various places where Asuch Water will be used.

In accordance with the present invention, the tank i9 is adapted to belheated by means of an electric resistance heater i3, of the tubularsheathed embedded type, which encircles the tank. lt is a feature of thepresent invention and as will later be pointed out, the heater isresiliently held against the tank so that good thermal conductivity willbemaintained therebetween under vdifferential expansion and contraction.

Briefly, the type heater employed comprises Van elongated tubularvmetallic sheath filled with compacted powdered electric-insulating,.heat-conductive refractory Inavterial in which is embedded a resistorconductor. Terminal pins 14- kare electrically and mechanicallyconnected to respective ends of the resistor and such pins usuallyextend beyond respective ends 'of the sheath to provide for thenecessary electrical connections to Ythe resistor. The sheath of thehea-ter will ordinarily be formed of such material, or Will be soannealed, that it may easily be bent about the tank.

While the present `invention is not limited to the specific typeelectric heater .herein disclosed, it is preferable, at the `presenttime, to employ heaters of this general type since they are economicalto manufacture, have high Watt density and long trouble-free life.

in order to improve thermal conductivity between the Water stored withinthe tank and the electric heater, the tank .shown in Figures l, 2 and 3is indented along a transverse axis to ,provide a groove 15 yin whichthe heater is adapted to be seated. Since the heater disclosed in thisembodiment is round in cross section, groove 15 has a rounded bottom toaccommodate the heater.

In order to simplify manufacture of the Water tank itil and for otherreasons which will later appear, it is preferable that groove 1S notextend completely around the tank. Since ymost tanks are made by forminga flat sheet of metal to a tubular form wherein opposed edges of thesheet are in juxtaposed relation and then welding or otherwise securingsuch edges together to provide a liquidtight joint, it will be clearthat considerable difdculty would arise if the groove intercepted thejoint in the tank.

It is contemplated that the tank of the present embodiment will beconstructed by forming a groove in the dat sheet of metal before it isformed to a tubular shape.

This groove will not extend completely across the sheet but willterminate short of the respective edges which are to be joined. Thesheet will then be formed to a tubular shape in the usual manner and thejuxtaposed edges Welded or otherwise secured together with nointerference from the groove.

As best seen in Figure 1, groove 15 runs out, or terminates, short ofthe tank seam 16 and the electric heater 13 is so positioned thereinthat its ends extend beyond the respective ends of the groove. In thepresent embodiment, terminal pins 14 extend inwardly of the ends of thesheath some distance and, since the resistor is confined to that portionof the heater intermediate the inner ends of the terminal pins, the heatgenerating portion of the heater is confined to that portion which isdisposed in groove 15. Means are provided for tensioning the heater 13about the tank to insure good thermal conductivity therebetween, suchmeans comprising clips 17 engageable with respective ends of the heater(but removable for a purpose to be disclosed) and a spring 18 forpulling the clip toward each other.

Each clip 17 (see Figure 4) comprises a metal plate having an aperture19 of a size to just pass a respective end of the heater, and anaperture 20 in which the spring 18 is adapted to be anchored. Atassembly, each clip 17 is adapted to be slid over a respective end ofthe heater and the clips pulled toward each other by means of spring 18anchored to and extending between the clips. As a result of the pull ofspring 18, each clip will be tilted Slightly with respect to the axis ofthe heater (see Figure 2). This will cause the aperture defining portionof the clips to tightly engage the heater and, in effect, lock the clipsthereto. Accordingly, the pull of spring 18 will be transmitted to theheater to tension it about the tank.

With the heater clamped about the tank, the ends will preferably be bentupwardly (see Figure 2) to facilitate making the usual (not shown)electrical connections to the projecting portions of the terminal pins14,

As shown in Figure 1, the jacket 11, which encases the tank 1t), isprovided with an opening 21 adjacent the ends of the heater 13 toprovide access to the latter and an opening is also provided in theinsulating material 12 at this point. A cover 22 normally overlies theopening 21 in the jacket 11, this cover being secured in place by anysuitable means but being removable to provide access to the ends of theheater.

In order to facilitate assembly of the heater 13 with the tank 1t),particularly after the tank is encased by the jacket 11 and theinsulating material 12, a plurality of plates 23 (herein shown to five)are welded or otherwise secured to the exterior of the tank so that theyextend tangentially thereof (see especially Figure 1). Each plate 23spans the groove 15 (see Figures 2 and 3) and serves to guide the heater13 to position as it is fed about the tank.

When it becomes necessary to replace the heater 13, it is only necessaryto remove the cover 22, remove the electrical connections (not shown)from the terminal pins 14, unhook spring 18 from the clips 17, removethe clips 17 from the heater and grasp the heater by one end and draw itfrom around the tank. Another heater will then be fed, as shown by thedot dash lines and by the arrow, to position within the groove and aboutthe tank. It will be clear that the tangentially projecting plates 23will serve to guide the leading end of the heater as it is fed about thetank through opening 21 and it will also be clear that the heater willpreferably be somewhat curved, prior to assembly, to facilitate thisoperation.

With the heater positioned within the groove 15, the clips 17 and spring18 will be assembled with the heater in the manner heretofore disclosed,the electrical connections made to the terminal pins 14 and cover 22replaced over opening 21.

In the interest of simplicity, the water heater disclosed in Figures 1,2 and 3 employs but a single electric heater 13; however, it is to beunderstood that as many heaters as desired may be disposed about thetank.

The embodiment of the invention disclosed in Figure is similar to thatshown in Figures l, 2 and 3; accordingly, similar parts are identifiedwith the same reference numerals but with the sux a appended. However,

in this embodiment, clips 17 and spring 18 have been replaced by aspring member 25.

As shown in Figure 7 and in full lines in Figure 6, spring member 2Scomprises a semi-circular band of spring steel or the like havingterminal portions 26 normally disposed in adjoining relation. Eachportion 26 has an aperture 27 of a size to just pass a respective end ofthe heater 13a. To assemble the spring member 25 with the heater 13a andassuming that the heater is disposed about the tank 10a with its ends inadjoining relation, the portions 26 of the spring member will be sprungapart, by any suitable means, to approximately the position shown by dotdash lines in Figure 6. Each portion 26 will then be slid over arespective end of the heater 13a and the portions thereafter allowed toreturn toward their normal positions. As the resiliency of member 25attempts to return portions 26, such portions will be tilted, withrespect to the axis of the heater, thus forcing the aperture deningportions of the member 25 into gripping engagement with the heater. Withthe portions 26 of member 25 tightly engaged with the heater, theresiliency of the member will draw the heater closely about the tank.

The water heater illustrated in Figure 8 is somewhat similar to thatdisclosed in Figures 1, 2 and 3 and comprises a water storage tank 28surrounded by heat insulating material 29 and encased in a jacket 30.Tank 28 is provided with a groove 31 which is similar to groove 15 intank 10 (Figure 1). However, in this embodiment, the groove is not asdeep as in the one in tank 10 for a purpose to appear.

An elongated electric heater 32, similar in all respects to heaters 13,13a of the heretofore disclosed embodiments, is adapted to be disposedin groove 31 in manner so that the ends of the heater extend beyond therespective ends of the grooves. In this embodiment, the means forholding the heater 32 within the groove and about the tank comprises ailexible band 33 of metal or other suitable material. Band 33 is hereindisclosed to be a ring-like, single piece of thin metal having adiameter somewhat greater than the diameter of the tank 28 and a widthsomewhat greater than the cross sectional diameter of the heater 32. Itis to be understood, however, that band 33 may be formed of an elongatedstrip having its ends fastened together by welding, riveting or thelike.

Band 33 is adapted to be tightened about the heater 32 by urging aportion of the band away from the tank. This will force the remainder ofthe band tightly against the heater.

As most clearly shown in fragmentary, enlarged view Figure 9, but asalso shown in Figures 8 and 10, a plate 34 having a threaded stud 35extending therefrom is adapted to seat against the wall of tank 28adjacent the adjoining ends of the heater 32. If desired, plate 34 maybe welded or otherwise secured to the tank; however, in the presentembodiment, plate 34 merely rests against the wall of the tank and isheld in position by the taut band 33.

Band 33 is apertured to pass stud 35 and a thrust plate 36 is slideablealong the stud 35 and is engageable with the inside of the band. A nut37 is threaded on stud 35 and a compression spring surrounds the studand is interposed between the nut and the thrust plate. It will beunderstood that as nut 37 is shifted along stud 35 in a direction awayfrom the tank, force will be exerted through spring 38 to urge a portionof the band away from the tank and to urge the remainder of the bandtightly about the heater. As best shown in Figure 10, the ends of theheater may be bent upwardly to facilitate making the necessaryelectrical connections thereto.

Replacement of heater 32 requires that nut 37 be shifted toward the tankto release the pressure exerted against band 33 and the heater graspedby one end and pulled from around the tank. The end of another heaterwill then be inserted between the tank and the band and the heater fedaround the tank until the ends thereof are positioned together at theopening in the jacket 30 'as shown. The band will then be tightened onceagain in the manner hereinbefore disclosed.

It will be noted that the groove 3-1 4and the band 33 together provide apassage about the tank through which the heater may easily be fed. It iscontemplated that the insulating material 29 will prevent shifting ofband 33 when it is loosened; however, if desired, one or more-clips maybe secured to the tank to maintain the band in position.

The water heater illustrated in Figure li is similar to the embodimentshown in Figures 8, 9 and 10; accordingly, similar parts are identifiedwith the sarne reference numerals but with the suix a appended. Theembodiment disclosed in Figure 11 differs from that heretofore disclosedin that the groove in the tank has been eliminated and the heater merelywrapped about the periphery of the tank. In order to increase thermalconductivity between the heater and the tank, a` portion of the heatermay be flattened, prior to assembly with the tank (see Figure 12).Additionally, since there is no `groove to guide the heater as it is fedabout the tank, band 33a may be curved transversely (see Figure 12) toprovide such a guide.

in the embodiment disclosed in Figure 13, an electric heater 40encircles a water storage tank 41 which is surrounded by heat insulatingmaterial 42 and encased in a jacket 43. Heater 40 may be attened toimprove its thermal conductivity with the tank and the heater may beheld about the tank by any suitable means. By way of example, heater 40may be held about the tank by means of the clips 17 and spring 18employed in the embodiment disclosed in Figures l, Z and 3 or by meansof the spring member 25 disclosed in Figures 5, 6 and 7.

ln order to provide for assembly and/or replacement of the heater in theembodiment of the invention illustrated in Figure i3, an annular opening44 is provided adjacent the heater 4t) in the jacket 43 and in theinsulating material 42. Normally, opening 44 is closed by adiscontinuous, generally ring-like band 45 (see also Figure 14) whichoverlies the opening. Insulating material may be cemented or otherwisesecured to the band 4S and this band will be held in place over theopening 44 by any suitable means.

By way of illustration, band 45 may have sufiicient resiliency tomaintain itself in position closing opening d4. However, if desired, anysuitable means may be ernployed to hold the band in position by drawingits adjoining ends together.

Replacement of heater 40 may easily be effected by springing band 45 andsliding it to the dot dash line position wherein it is spaced fromopening 44. Access to all portions of the heater 4t) will thus beeffected to permit removal of the old heater and installation of a newone. After the heater is clamped about the tank and the necessaryelectrical connections made, band 45 will be returned to its full lineposition wherein it overlies opening 44.

In view of the foregoing it will be apparent to those skilled in the artthat We have accomplished at least the principal object of our inventionand it will also be apparent to those skilled in the art that theembodiments herein described may be variously changed and modified,without departing from the spirit of the invention, and that theinvention is capable of uses and has advantages not herein specificallydescribed, hence it will be appreciated that the herein disclosedembodiments are illustrative only, and that our invention is not limitedthereto.

We claim:

1. A water heater construction, comprising a water storage tankgenerally circular in cross section and having its wall indented along atransverse axis to provide an inwardly directed, discontinuous groove,an elongated sheathed electric resistance heater having an intermediateportion positioned within said groove and having end portions extendingbeyond respective terminal portions of said groove, and meansresiliently holding said heater in seated relation within said groove toinsure good thermal conductivity between said heater and said tank.

2. A water heater construction, comprising a water storage tankgenerally circular in cross section and .having its wall indented alonga transverse axis to provide an inwardly directed groove, an elongatedsheathed electric resistance heater positioned within said groove, and

means 4for tensioning said heater longitudinally about said tank toinsure seating thereof within Said groove and to provide good thermalconductivity between said heater and said tank.

3. A water heater construction, comprising a water storage tankgenerally circular in cross section and having its wall indented along atransverse axis to provide an inwardly directed groove, an elongatedsheathed electric resistance heater positioned within said groove, andmeans engageable with respective end portions of said heater and urgingsuch portions in a direction to tension said heater longitudinally toinsure seating thereof within said groove and to provide good thermalconductivity between said heater and said tank.

4. A water heater construction, comprising a water storage tankgenerally circular in cross section and having its wall indented along atransverse axis to provide an inwardly directed, discontinuous groove,an elongated sheathed electric resistance heater having an intermediateportion positioned within said groove and having end portions extendingbeyond respective terminal portions of said groove, and means connectingthe end portions or' said heater ltogether and yieldably urging suchportions in a direction to tension said heater longitudinally to insureseating thereof within 'said groove and to provide good thermalconductivity between said heater and said tank.

5. A water heater construction, comprising a water storage tankgenerally circular in cross section and having its wall indented along atransverse axis to provide an inwardly directed, discontinuous groove,an elongated sheathed electric .resistance heater having an intermediateportion positioned within said groove and having end portions extendingbeyond respective terminal portions of said groove, a flexible ring-likeband completely encircling said tank and having one portion adjacent theend portions of said heater and another portion adjacent and overlyingthe intermediate portions of said heater, and resilient means interposedbetween said one portion of said band and the portion of said tankadjacent the terminal portions of said groove and yieldably urging saidone band portion away from said tank thereby drawing said other bandportion about said heater to insure seating thereof within said grooveand to provide good thermal conductivity between said heater and saidtank.

6. A water heater construction, comprising a water storage tank, anelongated sheathed electric resistance heater disposed about said tank,and means engageable with respective end portions of said heater andurging such portions in a direction to tension said heaterlongitudinally to insure good thermal conductivity between said heaterand said tank.

7. A water heater construction, comprising a water storage tank, anelongated sheathed electric resistance heater disposed about said tankand having end portions positioned in adjoining relation, and meansconnecting such end portions together and urging such portions in adirection to tension said heater longitudinally to insure good thermalconductivity between said heater and said tank.

8. A water heater construction, comprising a water storage tank, anelongated sheathed electric resistance heater disposed about said tankand having respective end portions positioned in spaced-apart, adjoiningrelation, and resilient means connecting such end portions together andyieldably urging such portions in a direction toward each other totension said heater longitudinally to insure 7 good thermal conductivitybetween said heater and said tank.

9. A water heater construction, comprising a water storage tank, anelongated sheathed electric resistance heater disposed about said tankand having end portions positioned in adjoining relation, and meansengageable with respective end portions of said heater and yieldablyurging such portions in a direction to tension said heaterlongitudinally to insure good thermal conductivity between said heaterand said tank, said means including clip portions each apertured to passa respective heater end portion and each adapted to be tilted to urge anaperture deiining portion of each clip portion into gripping engagementwith said heater, said means also including a resilient portion fortilting said cilp portions and for yieldably urging such portions towardeach other.

l0. A water heater construction, comprising a water storage tank, anelongated sheathed electric resistance heater disposed about said tankand having end portions positioned in adjoining relation, a clip memberbeing adapted to be tilted to urge the aperture dening portion thereofinto gripping engagement with said heater, and resilient meansengageable with said clip members to effect tilting thereof andyieldably urging the latter and respective end portions of said heaterin a direction to tension said heater longitudinally to insure goodthermal conductivity between said heater and said tank.

l1. A water heater construction, comprising a Water storage tank, anelongated sheathed electric resistance heater disposed about said tank,a flexible band completely encircling said tank and overlying saidheater, and means interposed between said tank and one portion of saidband and urging said one portion away from said tank thereby drawinganother portion of said band about said heater to insure good thermalconductivity between the latter and said tank.

l2. A water heater construction, comprising a water storage tank, anelongated sheathed electric resistance heater disposed about said tank,a flexible ring-like clamping band completely encircling said tank andoverlying 4 said heater, and resilient means interposed between saidtank and one portion of said band and yieldably urging said one portionaway from said tank thereby drawing another portion of said band aboutsaid heater to insure good thermal conductivity between the latter andsaid tank.

13. A water heater construction, comprising a water storage tank, anelongated sheathed electric resistance heater disposed about said tank,means holding said heater closely against said tank to insure goodthermal conductivity therebetween, a protective casing surrounding saidtank, said casing being open adjacent said heater and providing accessto the major portion of the latter to facilitate its replacement, andcover means normally closing said casing.

14. A water heater construction, comprising a water storage tankgenerally circular in cross section, an elongated electric heaterdisposed along a transverse axis about said tank, means holding saidheater closely against said tank to insure good thermal conductivitytherebetween, a protective casing surrounding said tank, said casinghaving a transverse opening adjacent said heater and providing access tothe major portion of the latter to facilitate its replacement, and covermeans including a band-like member normally encircling said casing andoverlying and closing the opening therein,

15. A water heater construction, comprising a water storage tankgenerally circular in cross section, an elongated sheathed electricresistance heater wrapped about said tank, a tiexible band completelyencircling said tank and overlying said heater and having an internalsize materially larger than the cross-sectional size of said tank toprovide for ease of assembly, and means for urging a portion of saidband radially outwardly of said tank to tighten the remainder of saidband about said heater to force the latter against said tank and providegood thermal conductivity therebetween.

References Cited in the file of this patent UNITED STATES PATENTS920,906 Bolling May l1, 1909 1,442,910 Steinhardt Jan. 23, 19231,704,413 Wait Mar. 5, 1929 2,452,214 Vogel et al Oct. 26, 1948

